i Detection of Smoke and Dust Aerosols Using Multi-sensor Satellite ...

with cloud in some areas along the CALIPSO path. In the Fig. 5.6, the BTD (12, 11μm) is
positive at three peaks with latitude 36.59 0 N - 39.79 0 N, 41.04 0 N - 44.02 0 N, and 44.640
N - 45.750 N, which is corresponding to dust aerosol areas. Between three peaks, the
BTD (12, 11μm) is negative which corresponding to cloud. Therefore, four dust aerosol
layers are found and marked with black circle in Fig. 5.7.
After the successful detection, the detail information about dust aerosol could be
further retrieved. Fig. 5.8 shows the total attenuated backscatter signal profile at 532 nm
in two locations: (40 0 N, 109.16 0 E) and (42 0 N, 108.51 0 E). The vertical profile for specific
location gives more detail and accurate values about dust aerosols. At the first location,
cloud (in dashed line rectangular) floated about 10.5 km above the sea level. At the
latitude 42 0 N, a large backscatter value at the altitude 2.5 km is corresponding to the dust
storm. By integrating the measurements of both sensors, the vertical and horizontal
information about dust aerosol can be retrieved. Table 5.3 summarized the vertical and
horizontal information about dust aerosols occurred in 2008 spring season in northwest
China, including height, averaged depth, width, and coverage.
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